One of the criticisms of the Palm Pre has been the lackluster volume of apps that are available for its WebOS platform. There were about a dozen released with the Pre, based on the individual deals Palm formed for pre-loaded (no pun intended) launch apps.

Today the company released its SDK for all. This is essentially what Apple has had in place since last year at about this time. It also comes one day after Microsoft announced the late-month availability of its app store. The degree to which Palm OS will attract developers comes down to many factors — the subject of a report we did recently.

Chief among them is the device’s penetration. App developers and companies entering the mobile world obviously want to reach the largest possible audience. As far as native apps go (SMS and WAP sites aside), iPhone gets you the most reach and engagement. Then again, there is lots of noise (i.e., 65,000 apps) in the Apple App store. More virgin territory awaits in Palm land.

It took Apple a year to get to 65,000 apps (and 1.5 billion total downloads), and Palm isn’t on pace with this so far. Its ability to catch up will be based largely on the popularity of the device itself, the availability on other carriers (Verizon) the capabilities of WebOS (exceeds the iPhone OS in some respects), and the development environment, whose characteristics will become known in the coming weeks.

Meanwhile, get ready for lots of Palm Pre apps to start rolling out. Not only will they be driven by device penetration, but they themselves will also drive Pre sales. It’s a self-perpetuating situation and the same can be said for the iPhone’s popularity: Apps provide thousands of little bits of functionality that boost the utility and appeal of the device itself.

More to come as we learn more.